Itadori is her friend. She's fat, and no one looks at her or makes friends. They say, "Ugh, how fat she is." Therefore, if we talk about someone's boyfriend falling in love with her, then this is out of the question at all. So she's just a fat girl from high school, like Itadori (he's from high school, too, like her). Itadori is very kind and friendly, who appreciates things in people that even they themselves do not notice. He's in her class too.